Question 27 (3 points)
if p equals an amount of energy, which equation correctly expresses n, or energy
efficiency?
a. n=p out + p in
b. n- pout - pin
c. n = p out / p in

C. n = P out / P in

Explanation:

Efficiency, in terms of energy, is generally defined as the amount of useful energy in output from a system divided by the amount of energy in input needed to make the system working.

Mathematically:

Or, since in our problem the energy is labelled with P,

No machine can have an efficiency of 1.0 (100 %), because not all the energy in input can be converted into useful output energy: part of it, in fact, is wasted because of internal frictions, and converted into thermal energy (heat).

the aurora is formed when charged particles emitted from the sun during a solar flare penetrate the earth's magnetic shield and collide with atoms and molecules in our atmosphere. these collisions result in countless little bursts of light, called photons, which make up the aurora.

auroras are generated by charged solar particles hitting molecules in earth's atmosphere. this usually happens in high latitudes, because our planet’s magnetic field tends to funnel these particles toward the poles. that’s why it can be experienced in northern ohio.